Transcript Do Now 4/7/08 - Howell Township Public Schools

Do Now 2/29/12
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Take out HW from last night.
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Copy HW in your planner.
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Practice worksheet #6.5 & Punchline worksheet #96
Text p. 256, #5-18 all
Quiz sections 6.4-6.6 Monday
A shoe store in NJ has a sale on sneakers for 15% off. If
the original price is$75 what is the total cost of the
sneakers with tax?
A shoe store in NJ has a sale on sneakers for
15% off. If the original price is$75 what is the total
cost of the sneakers with tax?
Sale price
Total Price
=
Original price
=
=
=
75
75
$63.75
=
Purchase Price
$63.75
$63.75
$68.21
–
–
–
+
+
Discount
(15% · 75)
11.25
+
Sales Tax
(63.75 x 7%)
4.46
Homework
Section 6.5 Practice worksheet
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1) $33.75
2) $2.50
3) 29%
4) $1,500
5) A. 9%
6) G. $785.71
7) C. $26.63
8) H. $3,000
Homework
Punchline worksheet #96
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1) a. 128
b. 36
c. 25%
2) $240
3) $37,500
4) a. $13.35
b. $31.15
5) a. $102.70
b. $1682.70
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6) Huey: 41.4%
Dewey: 41.7%
Louie: 45.7%
7) 27.8
8) $352
9) a. 35.3%
b. 262.5%
DIAPER ASH
Objective
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SWBAT compute simple interest
Section 6.6 “Simple Interest”
INTERESTthe amount of money charged for borrowing
or using money.
SIMPLE INTERESTthe product of the principal, the annual interest rate,
and the time in years.
I =P∙ r ∙ t
Principal – the amount
borrowed, loaned, or
in savings.
Time in years – when
time is less than a
year, write time as a
fraction of the year.
Rate of interest – the
percent charged or
earned.
Writing Time in Years…
I  P  r t
Time in years – when time is less than a year, write time as a
fraction of the year.
Write the months as a fraction of a year.
3 months
7 months
3 1

12 4
7
12
10 months
10 5
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12 6
Simple Interest
You have $3,000 in a savings account in a local
bank. The annual interest rate is 3%. How much
interest will the bank pay you in 4 years?
Principal = $3000
Interest rate = 3% or 0.03
Time = 4 years
I  P r t
I  3000  0.03  4
I  $360
Simple Interest
You borrowed $18,000 for a new car. The annual
interest rate is 12%. What is the interest you will
have to pay in two years to borrow this money?
Principal = $18,000
Interest rate = 12% or 0.12
Time = two years or 2
I  P r t
I  18000  0.12  2
I  $4320
Determining the Amount of Investment Time
Isaiah invested $3,500 in a mutual fund at a yearly
interest rate of 6%. He earned $945 in interest. For
how long was the money invested?
Principal = $3,500
Interest rate = 6% or 0.06
Interest = $945
I  P  r t
945  3,500 0.06 t
945  210t
4 .5  t
Account Balance
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When an account earns interest it is added to the
money in the account. The BALANCE (A) of
an account that earns simple annual interest is
the sum of the principal (P) and the interest (I).
A PI
Balance
Principal
Interest
Computing Total Savings
Nadia’s aunt deposited $325 into a savings account
as a college fund. How much will be in the account
after 8 years if the account earns simple interest of
7%?
Calculate interest first.
Find account balance.
I=P∙r∙t
I = (325)(0.07)(8)
I = $182.00
A = P+ I
A = $325 + $182.00
A = $507.00
Finding an Interest Rate
Suppose you save $1400 in a savings account that
earns simple annual interest. After 9 months, the
balance in your account is $1421. Find the annual
interest rate.
Principal = $1400
Balance = $1421
Time = 9 months
A PI
1421  1400  I
21  I
The interest rate is 2%
I  P  r t
9
21  1400  r 
12
21  1050 r
0.02  r
24
Homework
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Text p. 256, #5-18 all